101 questions about chemistry
by Erina-san
Summary: When Akiyama Sayuri, best student of her year, only gets the second highest grade in chemistry class, she decides the one who beat her will now become her archnemesis. Oikawa/OC
1. Chapter 1

**Chapter 1**

Contrary to popular belief, Akiyama Sayuri was not a robot.

In every school, every year, there is this one student who towers above all their peers, thanks to their excellent grades and borderline psychotic desire to know everything a subject has to offer. They are the kids who sit in front and remind the teacher the class had homework to do, the kids who hide during P.E. class instead of running and suffering like everyone else.

On the second month of her third year of high school, Akiyama Sayuri was a bundle of nerves. It was the day she would get the results of her beginning of the year exam. She had carefully studied, like always ever since she started going to school, making sure she understood and knew every little details that would _never_ be useful in her future life. She had faced the exams with an armour of confidence that looked like iron on the outside, but really it was like smashed potato on the inside. When the bell rang this Friday afternoon, students gathered under the huge board, trying to find their names and their rank. Some cried in relief when they saw they had passed the exam, barely. Others cried in disappointment because they would have to face the hell that was a retake.

There were a lot of people in front of Sayuri, especially some boys from the basketball or volleyball club or whatever was the game those boys liked to play with balls. They were as tall as trees and after a few minutes trying to bypass them she pushed her way through, ignoring their inquisitive and somewhat offended looks. They only shrugged when the girl didn't look at them at all.

Sayuri did an imaginary little victory dance in her head when she saw her name, ranked first. She was happy and relieved, because once again she was the best student of Aoba Johsai and that was the only thing that mattered. She then walked home happily, sparing sorry glances for the student that failed but she didn't think about it further. As she opened the door to her house, as usual the first to arrive home as her parents worked until late and her sister was currently at university in Tokyo, she picked up a letter at the front door. It came from school and had her name on it. She opened it and smiled when she realised it was only a summary of all the grades she had gotten at the exam. She checked by order of her favourite subjects : maths, best grade of the class, physics, best grade, litterature, best grade, history, best grade, geography, best grade, P.E class, absent because of medical reasons, and finally chemistry…

She gasped, her eyes widened to the size of saucers, and her mind failed to form a logical explanation.

Akiyama Sayuri had the second highest grade for the chemistry exam. She had a heart attack for five full minutes. Then, like a possessed girl, she slammed the door and ran out the street. For someone who hated sports and went as far as getting a doctor to help her skip P.E. class, she had a good running session that day. She arrived again at school as the sky was getting dark. The caretaker she had come to know quite well since she always arrived at school earlier than most people in the morning was closing the building.

"Can I help you?" The woman asked kindly.

"Yes!" Sayuri cried out. She showed her the results. "I just got this, and I found out I am first in all my subjects, except for chemistry where I am second best."

"Oh dear, it's wonderful, congratulations!"

"Thank you! Wait, no, that's horrible! I have never _not_ been first in chemistry, ever! Even though I hate the subject, I always at least managed to get the highest grades. There must be a mistake, please, I have to talk to the teacher!"

"I'm… I'm sorry Akiyama-chan, but I'm closing the school and all the teachers already went home. Maybe you should try on Monday."

Sayuri was on the verge of crying like a baby. In the end she had to agree to go home after the kind woman gave her sweets and tried to comfort her.

That evening, Sayuri barely ate anything at dinner, and spent it sending emails to her chemistry teacher.

On Monday, as soon as lunch break started, she blocked the door with her body before the teacher could get out.

"Well sensei, I'm very sorry to bother you but have you seen my emails and the horrible problem I am facing?"

The old woman sighed.

"Yes, Akiyama, I read all the dozen emails you sent me this weekend."

It had started very polite and enquiring to escalate quickly into desperate demands for explanation.

"There has been no mistake, you obtained the grade of 96/100. You did a serious and very good job."

_Very good, not excellent! It really is the worst day of my life! _Sayuri thought.

"But how am I only second best?" The girl had turned pale now.

The teacher looked at her curiously.

"Well it's obvious isn't it? Someone did better than you and got a hundred. So, see you in class on Wednesday."

She had said that casually as if she hadn't just told Sayuri of the greatest defeat of her life. The poor girl was crushed. She felt like she had failed her entire life. She felt like a pathetic, ordinary, mediocre student. Because if she wasn't the best student of the school, if she didn't get the highest grades in every single class, what was she good at? Who was she? Was she even Akiyama Sayuri anymore? She felt like dying right now and being burried forever in a coffin would be the best way to avoid the shame of being dethroned. Of course she was still the best of her year, but being only second in one subject put all her hard work to waste. The truth was clear to her: she was not worth anything anymore.

However, after the inital shock of losing her first place, another question quickly rose. _Who beat me? _There were two high risk suspects in her mind. First, Hara Mitsuko, a soft-spoken girl who always had correct answers for everything. She and Sayuri always had a rivalry going on, but they still liked each other in a way. The other suspect was Matsukawa Issei, a basketball player who always looked sleepy but was actually smart. He and Sayuri sometimes exchanged their ideas when a problem was particularly hard to solve and they both liked to make fun of teachers making stupid mistakes.

Since lunch break had already begun, and as the basketball team liked to eat on the rooftop, Sayuri made her way to Hara Mitsuko who was sitting with two friends, eating their bento.

"Hi, Hara-san" she started awkwardly. "Sorry to bother you, but can I ask you something quickly?"

The other girl was a little surprised but she smiled nonethelesss.

"Of course! What's wrong?"

Sayuri bit her lip then took a deep breath.

"Did you get 100 for the chemistry exam?"

In Sayuri's mind, it sounded exactly identical to "did you freaking beat me at chemistry?"

However Hara only looked embarassed.

"No, I got 90."

"Oh... okay, congratulations." So it was Matsukawa after all. Sayuri could not help feeling relieved. Even if Matsukawa was good at sport, and she was not, well she could accept being beaten by him at chemistry as well. After all, all his family members were scientists.

It didn't make the defeat sting less, but at least it was easier to swallow she guessed.

Unfortunately, Akiyama Sayuri didn't stop there. On Wednesday, when they were finally given back their chemistry papers, all graded, she found out her only mistake was in the last question. Actually it was not a mistake, Sayuri had skipped the question entirely because she had had no idea about the answer. They were asked to give the mechanism of the Cannizzaro reaction, something they had never seen in class. To think that Matsukawa knew the answer! It was very surprising and Sayuri only had to admit that his victory was only fair. However… she wanted to know what textbooks he used ouside of school, since they had proved efficient for the exam, that way she would not lose again.

That afternoon, after classes were over and students were expected to spend a few hours doing club activities, despite being the leader of the maths club, Sayuri decided to show up at the gym instead. She would be late for her own club, but she really did not want to go to a gym smelling of sweaty boys after basketball practice was over.

As she entered the gym, she realised a few things that she had gotten wrong previously (being wrong seemed like a horrible new habit of hers. Was she doomed to being ignorant now?!)

First, Matsukawa had never played basketball. He played volleyball. She felt betrayed by herself, after all these hours of boring classes challenging Matsukawa by giving him papers under the table where she had scribbled equations for him to solve, only for him to respond with more complicated equations, after all this, she had never known what sport he played. What a horrible girl she was. Now, on top of being a stupid student, she had also become an awful classmate (she had never dared to call him a friend, what if he laughed at her?).

Second thing she learned today, do not under any circumstances stand daydreaming in the middle of a gym when there is a volleyball practice going on. Mortal danger. Dangerous. Boom. Ouch.

It was like being hit in the face by a bullet.

Without realising what was happening, she fell to the floor, bright spots in her eyes and contusion in her head.

"Oh my god!" a boy said.

"Again? Trashykawa, how many random girls have you hit in the head for the past month?"

"So mean! I never do it on purpose, I don't know why it always happens!"

"Are you okay, Akiyama?"

Sayuri finally saw Matsukawa crouched in front of her, trying to check if she was badly injured.

"I'm fine" she said, although she felt like throwing up on whoever had hit her.

"I'm so sorry" the culprit finally appeared. It was Oikawa Toru, team captain, notorious flirt, and very, very bad at maths. She had seen his paper accidentally, and needless to say, his grade had made _her_ want to cry. "Can you stand? I will take you to the infirmary."

But Sayuri ignored him and turned to Matsukawa.

"What chemistry textbook do you use?"

Several members of the team were now surrounding them, the girl on the floor and the two boys beside her. Sayuri felt like she was suffocating in this forest of long legs. Matsukawa only gaped like a goldfish. Then he looked at his captain.

"We have to get her to the nurse."

"Agreed. She's nuts."

She gave both of them a nasty look.

"I am not crazy. Well at least not more than usual. You got a 100 at the chemistry test, Matsukawa, congrats. I just wanted to ask you how you study outside of school."

Her classmate looked surprised and scratched his neck.

"I didn't get a 100. I thought you did, Akiyama."

"What? No, that's impossible. If it's not me, or you, or Hara, then who?"

They looked at each other, confused.

"That would be me" an unexpected voice answered.

Slowly, confused, horrified, Sayuri turned to Oikawa.

"You?"

He winked at her.

"Yeah, surprising right? I learned the Cannizzaro reaction in _101 questions about chemistry_. Very informative and well explained, I strongly recommend this book!"

Sayuri looked at Matsukawa to know if his friend was joking. The boy only smiled sheepishly and shrugged. Sayuri looked at Oikawa.

"Call the nurse!" she snapped, dizzy.

So, to conclude, after this magnificently terrible week, Oikawa Toru had dethroned her in chemistry, made her feel like an idiot and hit her in the head with a volley ball, damaging many of her precious brain cells. It was decided then, there was no going back, he would hear about her again, because Sayuri would definitely get her revenge on him.

* * *

**AN: here's to all the OCs who received a ball in their heads.**


	2. Chapter 2

**Chapter 2**

Contrary to popular belief, Oikawa Toru wasn't petty nor arrogant. He just happened to enjoy being a pain in the ass to people who were considered geniuses.

To be honest, after injuring one of his classmates on Wednesday during practice, he did feel guilty. He was a decent human being after all. Of course, he had made up to the girl by being his charming self and by personally taking her to the infirmary. He even stayed there for ten minutes. Not that he wanted to brag, but his behaviour had been perfectly considerate and would make some people jealous. (Because most girls at Aoba Jousai would sell a kidney to spend just a moment alone with the great Oikawa-san.)

After that, he thought she had forgiven him, even though he was sure no one on this planet could ever be mad at him for a long time. Not even Iwa-chan, he hoped. However, he didn't know Akiyama Sayuri yet.

On Thursday, nothing out of ordinary happened, at least, that was what Oikawa decided to think. He felt oddly watched during the day but maybe it was just his fame getting to his head.

Things got weird on Friday. When he had arrived that morning, after greeting his friends, he quickly made it to his seat since class was starting soon. He had never really payed attention before that fateful day but Akiyama was sitting just behind him in class. Her forehead was still a little bruised where the ball had hit her. Still feeling somewhat guilty, even after his fantastic gentlemanly manners with her, he decided to be nice to her. She would surely enjoy the attention.

"Hi there, Akiyama" he smiled at her. She was scribbling something on her paper, despite the fact that class hadn't started yet but stopped abruptly to look up at him. She frowned. At the desk next to her, Matsukawa watched them, his eyes still sleepy. He stared at Akiyama when she remained silent for five seconds.

"Good morning, Oikawa." She glanced at Matsukawa as he nod, statisfied and gave him the riddle she had found and written for him. The greeting was cold and reluctant, but Oikawa just thought she was shy. Maybe she even had a crush on him, since he was the volleyball team's famous captain and she was only, well, a girl serious about her studies? He didn't know much else about her.

However later, during the entirety of the lesson, he could sometimes feel little kicks at his chair behind his back. They seemed accidental enough, so Oikawa didn't react, but they had never been so frequent during the first month of this schoolyear, although Akiyama had always been sitting behind him. Maybe she just had long legs she needed to stretch fifty times an hour.

Then, at lunch, just as he made it to the cafetaria to buy his favourite milk bread, the lady announced there were no more, a tragedy that had never happened to Oikawa in his life. He was crushed. Apparently someone had bought the whole batch. There was nothing to be done, he was just unlucky and crying would only wrinkle his pretty face.

(That afternoon Akiyama Sayuri gave milk bread to everyone in her maths club. That was the first time that their leader, usually distant and hard to befriend, had done such a thoughtful gesture. So you see, there definitely is kindness, ergo, goodness, in revenge.)

The weirdest thing was after practice, when all his team mates had already gone home, as Oikawa had stayed to work some more. But as he finally headed out he found himself locked inside the gymnasium. He frowned and tried to look for his keys but they were nowhere to be found. It was odd. Then it was downright creepy when the lights of the gym went off. Even though he would never admit it to anyone, Oikawa was a little bit afraid of the dark. (Yes, like his nine-year-old nephew Takeru.) The team captain only made it out after twenty minutes by jumping through a window in the locker room. What a weird day that was.

* * *

As Sayuri went home that day, she was feeling sweetly satisfied. She was happy all her clever little pranks had worked so perfectly, to the point where she now wondered why, in kids movies, the villains always failed in the end. It was so easy to be evil.

For once, her mother was home and preparing dinner. Ever since her older sister went to university in Tokyo two years ago, as the only remaining child at home, Sayuri had grown closer to her parents, something she would have never thought possible. As soon as she entered the kitchen, after a few words about her day, her mother urged her to pick up a list of groceries on the table. So once again, Sayuri put her shoes back on and headed for the convenience store.

* * *

It was already dark when Sayuri stopped in front of the store. Spring days had gone incredibly fast, and now that they were already two weeks into May, Sayuri wondered if the rest of her last year of high school would happen as fast as the first weeks. She hummed to herself as she walked between the alleyways of the quiet store. After picking up what her mother needed for dinner, Sayuri mechanically looked for her favourite snack. When she finally spotted it, she cursed under her breath. The chocolate was on the top shelf in a corner. She struggled for a while trying to grab it, standing on her toes and stretching her arm stubbornly. She considered giving up on her pride and asking for help when a hand shot above her head and took the prized chocolate. Someone was obviously a head taller than her and very apt at reaching things on top shelves.

"Thank-" Sayuri paused as her brain crashed for half a second and rebooted, "thank you Oikawa".

The boy smiled. It was a very symmetrical smile, on a very symmetrical face. The symmetry of that smile almost made amends for the inconvenience of meeting him at the moment. He had a dimple, she noticed.

"Funny that we meet here, huh?" he said with a cheery tone.

"Yes, I suppose."

But no matter how geometrically pleasing his face was, or esthetic, or visually satisfying (she firmly refused to call him handsome), she had no intention of being near him any more than necessary. Sayuri thought about something to say to leave him here and now. She didn't particularly want to hang out with her archenemy after stalking, no, investigating and playing pranks on him all day. Maybe a brutal "goodbye" now would suffice?

However it would not do because apparently Oikawa had finished shopping, just like her. Much to her despair both teenagers went to checkout together. The worst configuration had happened, they would have to _talk_.

"I did a little bit of research about you," Oikawa started casually. "Everyone says you're the smartest student of the school. They say you won lots of prizes back then. Some even consider you a _genius" _he said the word with a sickened grin and a challenging look in his eyes. But even if his words sounded like mere flattery, they were true nonetheless. Most of the time Oikawa didn't mind flattering people if that got them to do what he wanted, but in this case, it was a test. He had had some time to think and he was almost certain Akiyama had been the one annoying him all day. It was time to discover who she really was and why she was mad at him.

According to a very intelligent individual, in other words himself, the best way to get to know people is to make them feel uncomfortable and see how they react. He had over complimented her, so now there were only two options left: would Akiyama play humble and try to contradict him or would she respond with pride to the praise? In the first case she would prove to be a weak-willed girl lacking confidence, and in the second she would appear as an arrogant brat who was not as smart as she thought.

However Sayuri only glanced at him sideways as she payed for her groceries.

"And what do you think about me, Oikawa? Wait I know, you don't know anything. So maybe you should try to really get to know people instead of listening to gossips."

So that was the thirst option: she was a moralistic stuck-up. Not as bad as lacking confidence, but still enough to make him want to get on her nerves.

"So you do want us to get know each other better?" he smirked. She frowned. Gods, he was such a tiring boy.

"I don't think that's what I said. Just do as you want, I don't really care."

Not really a satisfactory answer, but Oikawa could deal with it. He chose a more direct approach.

"Why didn't you go to Shiratori Zawa? It's the best school of the prefecture and you clearly have the grades for that." He was genuinely curious about it. It made no sense for a maths genius to go to high school at Seijoh, not that it was a bad school. But Shiratori Zawa had a much higher level. So what kind of dirty secret did Akiyama Sayuri have? Did she fail the entrance exam before her first year? The idea was wonderful.

"I… I don't think that's any of your business." Sayuri had turned red. That only made Oikawa want to insist.

"Oh come on, I'm not going to make fun of you if you failed to get in you know!" Well only just a little bit. Genius always deserved a little bit of mockery.

"No."

"Come on!" he whined.

Sayuri sighed and glared at him as if he had just kicked a puppy.

"Fine. But don't go around opening your mouth to everyone about it. The truth is, I used to be at Shiratori Zawa during junior high. Then I went to Aoba Josai for high school."

She closed her eyes for the oncoming question.

"Why didn't you stay there?"

"That's the thing I won't tell you. That's something that concerns me and me alone. But no matter what happened… I like it here at Aoba so don't talk about Shiratori Zawa again," she said firmly. That was something she decided long ago not to talk about anymore, and she wouldn't open up to Oikawa Toru of all people.

"O- okay." Even Oikawa was uncomfortable at the moment. That girl was really too intense sometimes. He finished paying while trying to process what he had just heard. At least he could agree with her on the last point. Aoba Josai was much better.

"So, do you like this chocolate, Akiyama?" Oikawa tried to start the conversation again.

_Why bother talking if you're going to say something so useless?_ However Sayuri was too polite to say that out loud, even to her worst enemy.

"Yes it's my favourite."

"You shouldn't eat to much sweets, it's not good for your teeth." Oikawa said with a perfectly kind face. Sayuri glared at him. Who says that? That boy was so condescending.

"Sugar is what keeps the brain working. It's good for people who think a lot. Although of course I'm not surprised _you_ wouldn't need any sugar." She was always polite, at least that was what she liked to think, but Sayuri could never quite keep the bite out of her words when she was irritated.

Oikawa was dumbstruck. The doors opened and as she stepped out into the night, she turned to him. For the last hit.

"So… goodbye. Don't be too afraid of the dark." She added with a smirk.

Then she considered making a run for her house before this athletic boy, who was a good head taller than her and more muscular than the average young man decided to beat her up for insulting him. But surprisingly, he pointed at her and laughed like a detective on a kids show.

"Ha ha! You trapped yourself. So you admit you were the one who locked me in the gym! And you also kicked my chair all morning!"

_Oh no, I'm a cartoon villain! _She had stupidly admitted, it was done_. Well, if I have to go down…_

She grinned like a wolf.

"Yes I did. And I also bought all the milk bread at lunch."

Oikawa's eyes widened in horror. "But why? I tried to be nice to you. Is it because of the ball?"

"You just convinced yourself it would be an honor for any girl if you talked to them," she snapped. "As if we were pleading peasants and you were the king. Well you're the king of nothing, you arrogant brat. And it wasn't because of the ball, you idiot. You did much worse to me," she breathed heavily. "You did the only thing no one had ever dared. You took my rank in the chemistry exam! Because of you I was, I am number two! That stain will stay forever and my future is ruined. I'll never get accepted to my dream university! I will never forgive you!"

Oikawa was really angry now. "You did all this for a grade! Are you crazy? You're overreacting. Milk bread is worth so much more than this! You took the whole batch for yourself! You're so immoral, you disgust me."

"Fine! Then- then" Sayuri stuttered. "Just get lost!"

"_You_ get lost!"

After that, they parted and stomped to their respective homes. Both teenagers (who were almost turning eighteen) decided to sulk and never engage in any respectful exchanges again. Now it would be only revenge, attack and counter-attack. In other words it was a full-scale war. The possibiity of peace or a truce was inconceivable.

* * *

On Monday morning, Akiyama Sayuri, maths genius, who had agreed prior to the beginning of the year exam that she would tutor any student who had great difficulties in maths, was called by the teacher. He informed her there was only one student in her class who had failed the maths exam.

Akiyama Sayuri had to tutor Oikawa Toru.


End file.
